Set default delay for creating selfie to 3 minutes

Related discussion:
- https://www.reddit.com/r/uBlockOrigin/comments/bq49zi/

Author: gorhill

src/js/background.js

@@ -51,7 +51,7 @@ const µBlock = (function() { // jshint ignore:line
         manualUpdateAssetFetchPeriod: 500,
         popupFontSize: 'unset',
         requestJournalProcessPeriod: 1000,
-        selfieAfter: 11,
+        selfieAfter: 3,
         strictBlockingBypassDuration: 120,
         suspendTabsUntilReady: 'unset',
         userResourcesLocation: 'unset'